Nutritional Supplement

DHA

Also indexed as: Docosahexaenoic Acid

Possible Deficiencies

Premature infants who are not breast-fed are often DHA-deficient.8 A link has appeared between DHA deficiency and Alzheimer’s disease; however, no evidence at this time indicates that supplementation with DHA will help Alzheimer’s patients.9 Similarly, preliminary evidence shows that children with attention deficit disorder (ADD) have low DHA levels. However, no evidence demonstrates that DHA supplementation improves ADD.10 Preliminary evidence suggests that people with a variety of rare but related congenital diseases (Zellweger’s syndrome, neonatal adrenoleukodystrophy, and infantile Refsum’s disease) may be DHA-deficient, and may even benefit from DHA supplementation.11 Many doctors believe the diets of most people eating a Western diet do not provide optimal amounts of omega-3 fatty acids.

At least four studies have reported a reduced blood level of omega-3 fatty acids in people with depression.12,13,14,15

Side Effects

While those with heart disease and diabetes often benefit from fish oil (the primary source of DHA in the diet),16,17 such people should check with their doctor before taking more than 3 or 4 grams of fish oil per day for several months. Elevations in blood sugar have sometimes been reported,18 though this may simply be due to small increases in weight resulting from high dietary fish oil.19 While DHA combined with EPA from fish oil consistently lowers triglycerides, it occasionally increases LDL cholesterol.20

According to a report in a Japanese medical journal, three people at high risk for colon cancer developed a variety of cancers after one to two years of supplementation with DHA.21 To date, this report has not been confirmed by other researchers. To the contrary, test tube studies report that DHA is toxic to cancer cells22 and may someday be considered as an adjunct to conventional treatment for cancer.23 Similarly, animal studies suggest that DHA may inhibit cancer.24

References

1. Reisbick S, Neuringer M, Hasnain R, Connor WE. Home cage behavior of rhesus monkeys with long-term deficiency of omega-3 fatty acids. Physiol Behav 1994;55:231-9.

2. Stevens LJ, Zentall SS, Abate ML, et al. Omega-3 fatty acids in boys with behavior, learning, and health problems. Physiol Behav 1996;59:915-20.

3. Hamazaki T, Sawazaki S, Itomura M, et al. The effect of docosahexaenoic acid on aggression in young adults. A placebo-controlled double-blind study. J Clin Invest 1996;97:1129-33.

4. Sawazaki S, Hamazaki T, Yazawa K, Kobayashi M. The effect of docosahexaenoic acid on plasma catecholamine concentrations and glucose tolerance during long-lasting psychological stress: a double-blind, placebo-controlled study. J Nutr Sci Vitaminol 1999;45:655-65.

5. Jorgensen MH, Hernell O, Hughes E, Michaelsen KF. Is there a relation between docosahexaenoic acid concentration in mothers' milk and visual development in term infants? J Pediatr Gastroenterol Nutr 2001;32:293-6.

6. Gibson RA, Makrides M. Long-chain polyunsaturated fatty acids in breast milk: are they essential? Adv Exp Med Biol 2001;501:375-83.

7. Harris WS, Connor WE, Lindsey S. Will dietary w-3 fatty acids change the composition of human milk? Am J Clin Nutr 1984;40:780-5.

8. Crawford MA, Costeloe K, Ghebremeskel K, et al. Are deficits of arachidonic and docosahexaenoic acids responsible for the neural and vascular complications of preterm babies? Am J Clin Nutr 1997;66(4Suppl):1032S-41S [review].

9. Soderberg M, Edlund C, Kristensson K, et al. Fatty acid composition of brain phospholipids in aging and in Alzheimer's disease. Lipids 1991;26:421-5.

10. Stevens LJ, Zentall SS, Deck JL, et al. Essential fatty acid metabolism in boys with attention-deficit hyperactivity disorder. Am J Clin Nutr 1995;62:761-8.

11. Martinez M, Vazquez E. MRI evidence that docosahexaenoic acid ethyl ester improves myelination in generalized peroxisomal disorders. Neurology 1998;51:26-32.

12. Maes M, Smith R, Christophe A, et al. Fatty acid composition in major depression: decreased omega 3 fractions in cholesteryl esters and increased C20: 4 omega 6/C20:5 omega 3 ratio in cholesteryl esters and phospholipids. J Affect Disord 1996;38:35-46.

13. Edwards R, Peet M, Shay J, Horrobin D. Omega-3 polyunsaturated fatty acid levels in the diet and in red blood cell membranes of depressed patients. J Affect Disord 1998;48:149-55.

14. Peet M, Murphy B, Shay J, Horrobin D. Depletion of omega-3 fatty acid levels in red blood cell membranes of depressive patients. Biol Psychiatry 1998;43:315-9.

15. Maes M, Christophe A, Delanghe J, et al. Lowered omega-3 polyunsaturated fatty acids in serum phospholipids and cholesteryl esters of depressed patients. Psychiatry Res 1999;85:275-91.

16. Leaf A, Weber PC. Cardiovascular effects of n-3 fatty acids. N Engl J Med 1988;318:549-57 [review].

17. Malasanos TH, Stacpoole PW. Biological effects of omega-3 fatty acids in diabetes mellitus. Diabetes Care 1991;14:1160-79.

18. Schectman G, Kaul S, Kassebah AH. Effect of fish oil concentrate on lipoprotein composition in NIDDM. Diabetes 1988;37:1567-73.

19. Toft I, Bonaa KH, Ingebretsen OC, et al. Effects of n-3 polyunsaturated fatty acids on glucose homeostasis and blood pressure in essential hypertension. Ann Intern Med 1995;123:911-8.

20. Harris WS, Zucker ML, Dujovne CA. Omega-3 fatty acids in type IV hyperlipidemia: fish oils vs. methyl esters. Am J Clin Nutr 1987;45:858 [abstract].

21. Akedo I, Ishikawa H, Nakamura T, et al. Three cases with familial adenomatous polyposis diagnosed as having malignant lesions in the course of a long-term trial using docosahexanoic acid (DHA)-concentrated fish oil capsules. Jpn J Clin Oncol 1998;28:762-5.

22. Kafrawy O, Zerouga M, Stillwell W, Jenski LJ. Docosahexaenoic acid in phosphatidylcholine mediates cytotoxicity more effectively than other omega-3 and omega-6 fatty acids. Cancer Lett 1998;132:23-9.

23. Bougnoux P, Germain E, Hubert B, et al. Cytotoxic drugs efficacy correlates with adiposte tissue docosahexanenoic level in locally advanced breast carcinoma. Br J Cancer 1999;79:1765-9.

24. de Bravo MG, de Antueno RJ, Toledo J, et al. Effects of an eicosapentaenoic and docosahexaenoic acid concentrate on a human lung carcinoma grown in nude mice. Lipids 1991;26:866-70.

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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2024.